Alloy



an allee-containing about 12% "Tl/wt ci @M in. two inches, bothas l the balance eommereial alnmimun,

Patented Aug. 3, 1926. i

UNITED STATES nanna moz, or CLEVELAND, omo,

ASSIGNOB TO ALUMINUM COHPANY Oil' .AMLER-` 1 IGA., 0F PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA..

ALLOY.

No Drawing;

My invention relates to aluminum base alloys containing silicon and other metals and possesein the capabilitf of 'having their grain re ned and physical properties im B proved by an alkali metal treatment. More especially it relates to an aluminum base allo;r containing topper, manganese and a sub- Stantial amount of silicon.

ln my prior Letters Patentv No. 1,387,900,

l0 I discloee'd, an aluminum base alloy contain ing silicon which had had its grain rened audits physical properties improved by an alkali metal treatment involving treatin the molten metal with. a luorine compoun le of an alkali. metal. Another alkali metal treatment 'for similarly improving aluminum silicon alloys has been disclosed in Patent No. 1,410,461. Aluminum silicon alloys which have been subjected to an alkali metal -20 treatment are generally referred to as modied alloys.

.lilly present invention ie `based on the diseovery that aluminum silicon alloys oontaining small amountsof co perand man-` tll ganeee are not only suecepti le toimproves ment by an alkali metal treatment with theettendant retention of the'iluidity and much;

euohalloys but when so f of the ductility oli treated possess greatly increased tensile 3o strength and hardness' as compared with aluminum silicon alloys. l

a specifie illuetratiou. of my invention,

l of silicon,

manganese andA 1MM; copper, the

subjected to an ailmli metal treatment and cast inA a permanent mold. It attained a tenVv eile etrenth ot about 41,000 pounds per square inc and an elongation of about 43&% measuredin stan ard toet bars. vflfluese maximum properties were retained during several 1re-melting and reoaetine operations "Without :further eubjeen tion. o the molten. metal. to the alkali treat,` el: ment.

Another alloggi conte-lining about 12% eiltcou,l%"l.eopper ate tetti manganeee, with when metal treatmelilt and subtracted to the allteli .'15, t cant in a permanent mold, attained a tensile leti'eugth et about 5000 pounds peiW square inch and au elongation of about 61/ in two tnobee. 'fibra alloyr oleo retained tie abv orties of the alloys as described hereinabove.

Application med December 179, 19M. Serial Io. 757,060.

tained. strength and elongation during rev melti and recastingi operations without 5e being urther subjected" to the alkali metal treatment but, as was the case with the above composition, gradually'lost v4the same `as the reaction products of that treatment were eliminated from the alloy.

I have found that copper and manganese 'in certain amounts may be employedadvan w ta eousl with aluminum base alloys oon tainin etween about 3% and about 15% of silicon. The copper may vary between about 1/2% and 3% and the manganese may *vary between about 116% and 1%. The ropertles 'deslred in any castingof this al oy will, of course, determine-to some extent the amount and proportion of the cop Eer, sillcon and manlganese to be em lo ed ut where good tensi estrength and flil'rlity and fair elongation are desired, I prefer to use about 12% of silicon, 1%?6 ofcopper and about 1/2% of manganese.` Such an alley Wlll, when cast 1n 'a permanent mold, ossess a hardness of about 70 Brinell, which is highertlian the hardness of most im" roved or modified silicon alloys known eretofore.

Various additional metals such as cobalt, uramum, tun sten, molybdenum may be added in ema quantities to the foregoing alloys without harmful eiie'ct on the prop;

Having tliua desorilied my' inventiomwhat I desire' to secure by Letters Patent is de fined in what is claimed.

41. An 'aluminum base alloy containing beN tween about 3%'and about 15% of silicon, and copper and manganese totalling from almut 5% to 4% the co per constituting at least about .5% of the a o t it. tu aluminum base alloy containing beM tweenaliout We and about 15% of silicon, between about 0.5% and 3% 4of copper an between about 0.25% and about 1.0% ot managaueee.

il. .en aluminum bate alloy containing be twee about ll% and about 15% of: eihcoe between about 1.0% and 1.5% of copper and about 0.5% of manganese. f

et. en aluminum baee alloy containing 3% to '1.25% et eilicon, 1.0% to 1.5% of copper tot and 0.5% et manganeee.

Wit

Ag Y 1,595,058

5. .Anv aluminum base alloy containing and characterized, when cast in a Irermanen; 12% silicon, 1.25% of copper and 0.5% manmold, b having a tensile strengt of about 10 gallese. 40,000 1 s. per square inch, an elongation of 6. A modified aluminum base alloyconabout 4%, and a hardness of about 70 Brin- 5 taining copr in appreciable amounts not ell.

exceeding a. ut'3%, manganese in eppre- In testimony whereof I hereunto affix my oiableamounts'not exceeding about 1%, and signature this 16th day of December, 1924. between about 3% and about 15% of silicon ALADAR PACZ. 

